The invention relates to fluid distribution valves of the type which receive pressurized liquid into a closed chamber via an inlet port and sequentially open and then close each of a plurality of outlet ports of the closed chamber, and more particularly to an improved distribution valve that produces very little pressure drop from the inlet opening to a presently opened outlet port.
Multiple outlet fluid distribution valves that receive fluid under high pressure through an inlet port and distribute the fluid through sequential outlet ports are commonly used in self-cleaning swimming pool systems. In such systems, swimming pool water is pumped at high pressure (typically about 20 to 40 pounds per square inch) into the inlet port of the distribution valve. The outlet ports are coupled by lengths of PVC pipe to spaced cleaning heads that are installed in the bottom of the swimming pool and which eject rotary jets of high pressure water along the pool bottom to effectively sweep circular areas around each cleaning head. The state-of-the-art is believed to be best exemplified by commonly assigned U.S. Pat. No. 4,523,606 (Gould et al.), June 18, 1985 and U.S. Pat. No. 4,570,663 (Gould et al.), Feb. 18, 1986, both of which are incorporated herein by reference. Although the structure and technique of U.S. Pat. No. 4,570,663 represents a substantial improvement in solving the problem of oscillatory movement of valve balls onto and off of their seats as a result of sudden reversals of momentum of fluid in long lines, the structure described requires a considerable amount of torque to be applied to the cam that sequentially lifts the valve balls to open the successive ports. Any technique that would reduce the stresses on the filter/cleaning system and the gears would be desirable.
Accordingly, despite the progress made in developing a low cost, highly reliable multi-port distribution valve that meets the needs of the art of providing self-cleaning swimming pool systems, there remains a need for further improvements to solve the above-mentioned problems.